BoilerFaultCodesIdeal uP Fault Code
Also written as UP — same fault.
The Ideal uP fault code means: your boiler is currently stuck in its internal computer programming mode and hasn't been set up to operate as a heater yet.. It appears on 5 Ideal models in our database.
Technical description: Display shows uP on power on (PCB programming mode)
What causes the Ideal uP fault?
This fault occurs when a newly installed or replacement control board has not been told which specific boiler model it is living in. Because the same board is used across many different models, it remains in a 'blank' programming mode and refuses to fire until the correct configuration code is entered. The most common reason is that a technician has just replaced the board but hasn't finished the final software setup.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Search the official register for a qualified engineer in your area.
Gas Safe Register →Ideal models that show the uP fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal uP fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026